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18#include <linux/err.h>
19#include <linux/i2c.h>
20#include <linux/module.h>
21#include <linux/mod_devicetable.h>
22
23#include <linux/iio/iio.h>
24#include <linux/iio/buffer.h>
25#include <linux/iio/trigger_consumer.h>
26#include <linux/iio/triggered_buffer.h>
27#include <linux/regulator/consumer.h>
28
29struct adc081c {
30 struct i2c_client *i2c;
31 struct regulator *ref;
32
33
34 int bits;
35
36
37 struct {
38 u16 channel;
39 s64 ts __aligned(8);
40 } scan;
41};
42
43#define REG_CONV_RES 0x00
44
45static int adc081c_read_raw(struct iio_dev *iio,
46 struct iio_chan_spec const *channel, int *value,
47 int *shift, long mask)
48{
49 struct adc081c *adc = iio_priv(iio);
50 int err;
51
52 switch (mask) {
53 case IIO_CHAN_INFO_RAW:
54 err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
55 if (err < 0)
56 return err;
57
58 *value = (err & 0xFFF) >> (12 - adc->bits);
59 return IIO_VAL_INT;
60
61 case IIO_CHAN_INFO_SCALE:
62 err = regulator_get_voltage(adc->ref);
63 if (err < 0)
64 return err;
65
66 *value = err / 1000;
67 *shift = adc->bits;
68
69 return IIO_VAL_FRACTIONAL_LOG2;
70
71 default:
72 break;
73 }
74
75 return -EINVAL;
76}
77
78#define ADCxx1C_CHAN(_bits) { \
79 .type = IIO_VOLTAGE, \
80 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
81 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
82 .scan_type = { \
83 .sign = 'u', \
84 .realbits = (_bits), \
85 .storagebits = 16, \
86 .shift = 12 - (_bits), \
87 .endianness = IIO_CPU, \
88 }, \
89}
90
91#define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \
92 static const struct iio_chan_spec _name ## _channels[] = { \
93 ADCxx1C_CHAN((_bits)), \
94 IIO_CHAN_SOFT_TIMESTAMP(1), \
95 }; \
96
97#define ADC081C_NUM_CHANNELS 2
98
99struct adcxx1c_model {
100 const struct iio_chan_spec* channels;
101 int bits;
102};
103
104#define ADCxx1C_MODEL(_name, _bits) \
105 { \
106 .channels = _name ## _channels, \
107 .bits = (_bits), \
108 }
109
110DEFINE_ADCxx1C_CHANNELS(adc081c, 8);
111DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
112DEFINE_ADCxx1C_CHANNELS(adc121c, 12);
113
114
115enum adcxx1c_model_id {
116 ADC081C = 0,
117 ADC101C = 1,
118 ADC121C = 2,
119};
120
121static struct adcxx1c_model adcxx1c_models[] = {
122 ADCxx1C_MODEL(adc081c, 8),
123 ADCxx1C_MODEL(adc101c, 10),
124 ADCxx1C_MODEL(adc121c, 12),
125};
126
127static const struct iio_info adc081c_info = {
128 .read_raw = adc081c_read_raw,
129};
130
131static irqreturn_t adc081c_trigger_handler(int irq, void *p)
132{
133 struct iio_poll_func *pf = p;
134 struct iio_dev *indio_dev = pf->indio_dev;
135 struct adc081c *data = iio_priv(indio_dev);
136 int ret;
137
138 ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
139 if (ret < 0)
140 goto out;
141 data->scan.channel = ret;
142 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
143 iio_get_time_ns(indio_dev));
144out:
145 iio_trigger_notify_done(indio_dev->trig);
146 return IRQ_HANDLED;
147}
148
149static void adc081c_reg_disable(void *reg)
150{
151 regulator_disable(reg);
152}
153
154static int adc081c_probe(struct i2c_client *client,
155 const struct i2c_device_id *id)
156{
157 struct iio_dev *iio;
158 struct adc081c *adc;
159 struct adcxx1c_model *model;
160 int err;
161
162 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
163 return -EOPNOTSUPP;
164
165 model = &adcxx1c_models[id->driver_data];
166
167 iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
168 if (!iio)
169 return -ENOMEM;
170
171 adc = iio_priv(iio);
172 adc->i2c = client;
173 adc->bits = model->bits;
174
175 adc->ref = devm_regulator_get(&client->dev, "vref");
176 if (IS_ERR(adc->ref))
177 return PTR_ERR(adc->ref);
178
179 err = regulator_enable(adc->ref);
180 if (err < 0)
181 return err;
182
183 err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable,
184 adc->ref);
185 if (err)
186 return err;
187
188 iio->name = dev_name(&client->dev);
189 iio->modes = INDIO_DIRECT_MODE;
190 iio->info = &adc081c_info;
191
192 iio->channels = model->channels;
193 iio->num_channels = ADC081C_NUM_CHANNELS;
194
195 err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL,
196 adc081c_trigger_handler, NULL);
197 if (err < 0) {
198 dev_err(&client->dev, "iio triggered buffer setup failed\n");
199 return err;
200 }
201
202 return devm_iio_device_register(&client->dev, iio);
203}
204
205static const struct i2c_device_id adc081c_id[] = {
206 { "adc081c", ADC081C },
207 { "adc101c", ADC101C },
208 { "adc121c", ADC121C },
209 { }
210};
211MODULE_DEVICE_TABLE(i2c, adc081c_id);
212
213static const struct of_device_id adc081c_of_match[] = {
214 { .compatible = "ti,adc081c" },
215 { .compatible = "ti,adc101c" },
216 { .compatible = "ti,adc121c" },
217 { }
218};
219MODULE_DEVICE_TABLE(of, adc081c_of_match);
220
221static struct i2c_driver adc081c_driver = {
222 .driver = {
223 .name = "adc081c",
224 .of_match_table = adc081c_of_match,
225 },
226 .probe = adc081c_probe,
227 .id_table = adc081c_id,
228};
229module_i2c_driver(adc081c_driver);
230
231MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
232MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");
233MODULE_LICENSE("GPL v2");
234
